An approach for traffic characterization in generalized processor sharing networks

This work is motivated by the increasing need of end-to-end performance bound provisioning in multi-service networks. Providing performance bounds in a networking environment is a difficult problem as traffic is bursty and its dynamics is far more complex than in a single server environment. As end-to-end bounds are basically based on local switch guarantees, computation of local performance bounds requires the knowledge of traffic conditions at inputs of each switch. This paper investigates the problem of traffic characterization of arbitrary topology networks that employ the generalized processor sharing (GPS) scheduling discipline at each node. The study focuses on the derivation of internal (at inputs of switches) traffic descriptors of sessions which are originally leaky bucket constrained at the network edge. Allowing arbitrary weight assignment of sessions the analysis classifies GPS networks into different sets by means of various stability conditions. Methods are presented for the determination of internal traffic parameters in cyclic, acyclic networks with and without virtual feedback. Numerical examples are shown for the illustration of our algorithmic approach for the above mentioned scenarios as well as for end-to-end delay computation of sessions